Welcome back. Exactly 7:42. And it's time for our series, "Gma" investigates. And today, the dirty secrets of flying. Inside confessions from a flight attendant about the nasty germs that could be flying with you. ABC's Mara schiavocampo has more. Good morning to you, Mara. Reporter: Good morning, Lara. This summer, air travel will be sizzling. An estimated 210 million passengers are expected to fly from June to September. Those are the highest levels in six years. So, just what do you really need to know before flying off into the sunset? On this "Gma" confessions, a veteran flight attendant shares all of her secrets. Air travel. An estimated 2 million of us fly each day. And after the release of Auburn university's study this week that suggests that bacteria that can cause infections, pneumonia, diary Ya and even death, for up to a week, many were wondering are there other secrets of the skies? Enter heather Poole, author of "Cruising attitude." This morning, at the world's biggest aviation theme studios, air Hollywood, she shares with "Gma" investigates, all of the little-known things you need to know before taking off. Our job is so unlike any other job. Reporter: First up, cabin chills. While many passengers get cold onboard, one particular spot is worse than the rest. Exit row's always the coldest row because the seal makes it colder. Reporter: Poole shares if you opt for an airline blanket, it might not be clean. They're not washed after every flight? No. Reporter: If it's in that plastic that means it's clean? Yes. Reporter: Those blankets might not be the only things that are dirty. I've seen passengers change their dirty diapers on the table. This tray table gets abused. Reporter: We reached out to several major carriers who say the planes are cleaned regularly. If your seat is all the way in the back, you might not get the best service. We do run out of thing. We might run out of food. Reporter: If you're in the back, you might get very little? Right. Reporter: Or if you get trapped in the bathroom, they can come to their rescue. You just opened that from the outside. I can. Reporter: But Poole says the most important secret of all is this one. If someone says hello and makes eye contact, I want to give them water and extra -- whatever I can give them, I'll give them. Reporter: Make sure you're a friendly flier. And if sitting in the back weren't bad enough, that's also where you'll feel the most turbulence. Poole says she brings everything she needs onboard with her. And she never puts her food directly on the tray tables, which is probably good advice. I would pack a portable table or eat on your lap. Great advice. And coming up here, George's

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